Fig. 2

Seeding of established tumors by CTCs. A A diagram of contralateral-seeding experiment. Unlabeled and GFP/luciferase-expressing breast cancer cells were injected into contralateral No. 2 mammary glands as a “recipient tumor” and a “donor tumor”, respectively. B BLI of recipient tumors extracted from mice bearing the indicated GFP/luciferaseexpressing donor tumors. Color-range bars: photon flux. LM2: a lung metastatic derivative of MDA231. MCF7-BoM2: a bone-metastatic derivative of MCF7, CN34-BrM2: a brainmetastatic derivative of pleural effusion CN34, PyMT: cells derived from mammary tumors developed in MMTV-PyMT transgenic mice. C BLI of tumor-free and tumor-bearing mammary glands from mice bearing GFP/luciferaseexpressing donor tumors. n = 9–18. D Frozen sections of seeded MDA231-LM2 tumors were visualized by fluorescence microscopy. An entire tumor section and a higher-magnification image (× 10) of a selected field are shown. E A contralateral-seeding experiment was performed with RFP- and GFP-expressing. MDA231-LM2 cells. Frozen sections from RFP-labeled tumors were visualized under confocal microscopy at × 20. FA diagram to test mammary tumor seeding from lung metastases. GFP/luciferaseexpressing MDA231-LM2 cells were injected intravenously. Once lung metastases were established, unlabeled MDA231 cells were injected into a mammary gland No. 2. G Left: burden of CTCs derived from lung metastases in mice described in panel F. Relative levels of CTC were plotted against the luminescent signals of recipient tumors. Right: BLI of three representative recipient tumors (i, ii and iii) identified in the graph [36].The copyright of this image belongs to Reference [36]